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Single vs Twin

 
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vgrant



Joined: 07 Nov 2003
Posts: 6
City/Region: Georgetown
State or Province: SC
C-Dory Year: 2006
C-Dory Model: 25 Cruiser
Vessel Name: C-GRITS
PostPosted: Wed Nov 16, 2005 11:03 pm    Post subject: Single vs Twin Reply with quote

I would like to hear your thoughts on a single vs twin on the 25 cruiser. I boat on the southern coast where the wind and current are typically strong. I think I want twins for manevurability at the docks. Please advise.
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TyBoo



Joined: 23 Oct 2003
Posts: 5314
City/Region: Warrenton
State or Province: OR
C-Dory Year: 1996
C-Dory Model: 25 Cruise Ship
Vessel Name: TyBoo
Photos: TyBoo
PostPosted: Wed Nov 16, 2005 11:17 pm    Post subject: Reply with quote

The one vs. two has been talked over real good before, but it is mostly focused on the CD22. The CD25 as its own topic deserves a good hashing over, too.

I think twins on the CD25 would be great, but because they would be the larger blocks the overall weight would be a big concern. On the other hand, having one huge motor hanging in the center of the wide transom can be cause for worry. The upper mounting bolts on my CD25 130 have been pulled into the glass enough to crack the gelcoat. (Yep, they had big washers - now they have real big ones. Two SS plates at 3/8" x 4" x 8".)

Sounds like an ad for the new ETechs, doesn't it??

As to the maneuvering issue, sure, it could make it easier. But it really isn't too difficult to handle the 25 with one screw. Well, it was for a while until I got used to the bigger hull after finally getting the 22 figured out. I think that aspect would be down a ways on the priority list in deciding.

There is at least one owner on here who has twin Honda 90s on a CD25. It will be interesting to hear from him.

Thanks for bringing it up.

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TyBoo Mike
Sold: 1996 25' Cruise Ship
Sold: 1987 22' Cruiser
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Alasgun
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PostPosted: Thu Nov 17, 2005 9:39 am    Post subject: Single VS Twin Reply with quote

I too am setting up a new 25 footer. Being new to the game, I listened carefully to all the advise. The twins for reliability thing almost got me until it was pointed out just how reliable these new motors are and that a mechanical problem would most likely come from bad fuel! What settled it for me was when one of my friends told me how he had to come in on the kicker due to lower unit damage from an underwater object. (probably a rock) I started to think that if I had two lower units in the water at the same time, the likelihood of damage to both would be greater than one up and one down. Therefore I settled on a 150 Honda main with a 20 Honda as an emergency back up more so than a kicker. This way I can also provide an alternate fuel source and eliminate the bad fuel concerns. Mike on Huda Thunkit.
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BORIS POPOV



Joined: 19 Jan 2004
Posts: 5

C-Dory Year: 2005
C-Dory Model: 25 Cruiser
Vessel Name: C-BORY
PostPosted: Thu Nov 17, 2005 12:20 pm    Post subject: Reply with quote

Thought I would respond to this issue with another of the mutlitude of opinions on single versus twins. Being in aviation most of my life, the same never ending discussion on single v. twins on aircraft continues, but seems to be leaning toward high reliability singles in both aviation and marine markets.
In both aviation and marine, it seems most experienced boat/plane owners agree that though two engines provides some safety margin over singles, the chances of something going wrong with any engine doubles with twins, and having anything go wrong in the first place is exactly what must be avoided at all costs. As a case in point, the consensus in avaition is that the newer turbine engines have become so reliable that single turbine engine aircraft are replacing the more expensive and higher maintence cost reciprocating twins.
Prior to my ownership of CDories ( a 22 and now a new 25) I ran a 26 foot Tiarra Pursuit with twin 225 Johnson outboards, mostly in Lake Superior. Constant headache with one or the other engine requiring repairs. I chose a single 140 Suzuki ( being traded up to a 175...but that's another story) with a 9.9 kicker for the new CDory 25. I run the boat out of Cordova Alaska, where reliably and safety aren't just an afterthought, but a crucial aspect of traveling in those waters.
I had the CDory factory install a qucik disconnect in the gas line at the main tank connection. The same connectors are attached to the kicker so that if I have a fuel contamination problem ( which I agree is the most likely problem one will face with today's reliable outboards), I can disconnect the kicker from the main tank and connect to a separate 2.5 gal tank that I always carry on board. That small tank is checked for fuel quality by running it in the kicker once or twice a summer.
Hope this bit of input helps those facing this decision.
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MichaelOnTheClaraMae



Joined: 30 Oct 2003
Posts: 121
City/Region: Charleston
State or Province: SC
Photos: Clara Mae
PostPosted: Thu Nov 17, 2005 1:11 pm    Post subject: Reply with quote

I have had the Clara Mae for three years now with a single Honda 130 four stroke on her and no kicker. Although I think having twins would be great, I would stick with the same set up if I had it to do all over again.

For one, I really like my swim platform and use it all the time. I am not sure if you can have twins and a platform now but I was told you could not when I bought mine.

As far as reliability, I have SeaTow as my back-up. I have taken some pretty long trips and have nearly 800 hours on my 130 with no problems or interruptions. I do carry an extra prop. And in case I do lose power in rough seas, I carry plenty of anchor line and a sea anchor for deep waters.

As far as maneuvering, I think once you get familiar with the prop walk that is associated with prop rotation you can use it to your advantage. For example, the Clara Mae pulls to port when in reverse. Using this, I can spin her 180 degrees (bow to starboard) in just a few feet more than her own length. Docking to port is much easier for the same reason. Note twin screws that rotate the same way will produce prop walk as well.

Hope this helps!

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Michael


Last edited by MichaelOnTheClaraMae on Fri Nov 18, 2005 7:29 am; edited 1 time in total
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Sea Angel



Joined: 29 Dec 2003
Posts: 736
City/Region: Virginia Beach, VA
State or Province: VA
Photos: Sea Angel
PostPosted: Thu Nov 17, 2005 2:33 pm    Post subject: Reply with quote

Sea Angel here...
I have the CD25 with twin HONDA 90s, with 4 blade SS, 15", props.

All the points made here are all very valid; from maintenance cost for 2 engines & props, to operating techniques. This is where the decision works around to our application and desires.

The points that have driven me to the twin arrangement were..
1. Weight distribution across the stern
2. Low end torque, in that of more blade area for towing and manuvering
3. Reliability.. though by itself today this is not too much of a valid point
4. Electrical needs..
5. It looks good...

My application was primarily driven by the need to be able to manever in close spaces with counter winds and currents. This has proved itself invaluable here at my marina. I have to back into the slip for the fork lift retrieval. The marina is on a creek with hills behind and across from the docks.

The hull of the CD25 has a shallow [abt 10"] draft and a minor skeg with a flat bottom near the sterm. The sail area has caught me on several occasions when a gust came down the 'shoot' and forced me to abort the approach. This is no fault of the CD25, only the skill of the operator. I keep practicing. Like flying, the only bad landing is one where you come away with damage.. So far no damage or skuffs. I may work toward a helm position in the cockpit to help with my line of sight in the future.

On the reliability weakness question.. The only area I have is that of bad fuel. Where I refuel there is enough turn over to keep it fresh. Having only a single tank can shut me down, but I carry water/fuel separator filters and spares. With the NAVMAN FF system, I try to keep up with the twins operation; as well as using the water pressure gauge option [ I lost my earlier OB's water pump to too many plastic bags].

The FF readings I seem to get is in line with the larger singles. I spend most of my time abt 7kts with .7 to .8 g/h. At WOT I have 17.6 g/h at 24kts carring full water & fuel, 2 POB, 60' chain, 600' anchor line and a bunch of other First Mate "STUFF".

I hope I did not describe how the clock worked verses what time it is. There is a wealth of info on this site and many willing folks here to help you support the economy... Just spend wisely for your application, but be safe and happy with where you land.

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Art ka1rx
CBRAT #208
2005 CD25 #075 SEA ANGEL (SOLD)
USCGAUX (RET), USN(RET)
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ka1rx@verizon.net
SKYPE: Art.Bartlett4
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DaveS



Joined: 01 Nov 2003
Posts: 3204
City/Region: Arlington
State or Province: WA
C-Dory Year: 2004
C-Dory Model: 22 Cruiser
Vessel Name: Sea Shift
Photos: Sea Shift
PostPosted: Thu Nov 17, 2005 6:11 pm    Post subject: Reply with quote

MichaelOnTheClaraMae wrote:

For one, I really like my swim platform and use it all the time. I am not sure if you can have twins and a platform now but I was told you could not when I bought mine.


As I've mentioned in previous related threads, Les manufactured and installed a swim platform on our 22' Cruiser with twin engines and trim tabs, so I would suspect the same could be done for the 25'. (Pix of the swim platform are in the "Sea Shift" album).

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"Sea Shift"
C-Brat #16
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captd



Joined: 06 Nov 2003
Posts: 514
City/Region: Chain of Lakes
State or Province: MT
C-Dory Year: 1994
C-Dory Model: 22 Cruiser
Vessel Name: Kon Tiki
Photos: Hunky Dory
PostPosted: Thu Nov 24, 2005 12:24 pm    Post subject: Reply with quote

C-Brats,
Seems like all inputs on this topic are correct. I guess it boils down to what is a guy going to do with his boat. In risky water I raise one engine completely and shut it down. Than of course proceed with caution. If you are in a location where service is limited you may become an instant land lubber, which is no fun. Cry I had one expeirence which convinced me.
About 15 yrs ago, while enroute through 750 miles of the Bahamas and crossing the open sea to Jamaica on to Panama. We shut down engines one at a time to check oil. We found the starter had stuck on one engine and burned up. No way to start that engine and 300 to 400 miles of open sea to get to our destination. Because we had twin engines we made it, no worse for wear. Albeit much slower. These engines were 8V71,s Detroits. in a 45 ft. Chris.
Question......Is'nt two 40 Hondas about the same weight as a single 90? I forget. Thumbs Down Thumbs Up
CaptD

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100 ton Master
1986 Sport Craft 27 ft , 240 hrs Yanmar sold
2000 22 ft C-Dory (Hunky Dory) sold 2006
2007 25 R Ranger (Mis Dee) sold 2008
2009 25 R Ranger (Lucky Fin) sold
1994 22 ft C-Dory ( Kon Tiki )
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Chuck S



Joined: 01 Nov 2003
Posts: 309
City/Region: Cleveland
State or Province: OH
C-Dory Year: 2003
C-Dory Model: 16 Cruiser
Vessel Name: Amelia Anne
Photos: Amelia Anne
PostPosted: Fri Dec 02, 2005 11:06 pm    Post subject: Reply with quote

Ginger or Mary Ann?

Take your choice. I fly single engine airplanes. Twins won't fly on one any more than one will with none. It's a slow drive home on one engine of a twin boat. And your kicker will push the boat darn near as fast.

-- Chuck
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